Efficiency Assessment of Coagulants in the Removal of Arsenic from Water

Coagulation and flocculation process is one of the common methods used in water treatment plants used for treatment of surface waters. If performed correctly, this process can affect the removal of heavy metals and the removal rate will reach its maximum value. In the present study, the effect of coagulants dosage and different elements in water such as calcium and sulfate ions on the arsenic reduction process were assessed at different pH values. Jar test was used to determine the optimal dosage of coagulant and to assess the effect of parameters such as pH, coagulant dosage, temperature, stirring speed, etc. The reduction percentage of total arsenic in the presence of PAC was 10 to 15% more than Ferric Chloride. The results showed that in the case of the polyelectrolyte coagulants aid, the reduction rate was high. Soluble material in water had different impact on the reduction of arsenic concentrations with changes in pH values.